Simulators of physical systems have been used in the past for providing a training environment for physical systems that may be too costly or dangerous to learn by performing the actual activity. For example, a flight simulator may be used to teach a pilot skills used in flying an airplane without subjecting the pilot to the risk of damaging an actual airplane or injuring the pilot. However, editing a model of an airplane or a portion of an airplane for use in a simulator conventionally requires editing the model and testing the modified model within the full simulator, rather than testing only the modified component without having to run a full simulation. Further, conventional computer simulators do not allow the modification and testing of discrete elements of the model being simulated.